feat: consolidate testdrive-jsui to capabilities and implement plugin self-declaration

## Major Changes
- Moved all testdrive-jsui assets from root to capabilities/testdrive-jsui/
- Consolidated directory structure: js/, static/css/, static/images/, static/templates/
- Implemented plugin self-declaration (get_plugin_source_dir, get_asset_paths)
- Removed hardcoded plugin discovery from rendering.py
- Updated all asset paths to be relative to capability root

## Architecture Improvements
- Single source of truth for all testdrive-jsui assets
- Plugin declares its own location (no hardcoded paths)
- Generic plugin discovery using hasattr check
- Clean separation: all JS in .js files, no code mixing
- Standalone capability ready for independent use

## Files Changed
- markitect/plugins/testdrive_jsui.py: Added self-declaration methods
- markitect/plugins/rendering.py: Removed hardcoded discovery
- capabilities/testdrive-jsui/README.md: Added standalone usage documentation
- Moved 17 asset files to consolidated structure
- Deleted obsolete /testdrive-jsui/ root directory

## Testing
- All 17 assets verified and working
- Tested via CLI: markitect md-render --engine testdrive-jsui
- Full document rendering successful

Prepares testdrive-jsui to become a git submodule with proper dependency management.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

markitect/plugins/rendering.py

@@ -296,17 +296,21 @@ class RenderingEngineManager:
         return deployed_assets
 
     def _get_plugin_source_dir(self, engine_name: str) -> Optional[Path]:
-        """Get the source directory for a plugin."""
-        if engine_name == 'testdrive-jsui':
-            # Look for testdrive-jsui directory relative to current directory
-            candidates = [
-                Path('testdrive-jsui'),
-                Path(__file__).parent.parent.parent / 'testdrive-jsui',
-                Path('.') / 'testdrive-jsui'
-            ]
+        """
+        Get the source directory for a plugin.
+        Uses plugin self-declaration if available, no hardcoded paths.
+        """
+        engine = self.get_engine(engine_name)
+        if not engine:
+            return None
 
-            for candidate in candidates:
-                if candidate.exists() and candidate.is_dir():
-                    return candidate
+        # Use plugin's self-declared source directory if available
+        if hasattr(engine, 'get_plugin_source_dir'):
+            try:
+                source_dir = engine.get_plugin_source_dir()
+                if source_dir and source_dir.exists():
+                    return source_dir
+            except Exception as e:
+                print(f"⚠️ Error getting plugin source dir for {engine_name}: {e}")
 
         return None

markitect/plugins/testdrive_jsui.py

@@ -35,21 +35,45 @@ class TestDriveJSUIEngine(RenderingEnginePlugin):
         """Support edit and view modes."""
         return ["edit", "view"]
 
+    def get_plugin_source_dir(self) -> Path:
+        """
+        Return the source directory for this plugin.
+        This allows the plugin to declare its own location.
+        """
+        # Plugin is located in capabilities/testdrive-jsui/
+        return Path(__file__).parent.parent.parent / "capabilities" / "testdrive-jsui"
+
+    def get_asset_paths(self) -> Dict[str, Path]:
+        """
+        Return paths to asset directories relative to plugin source.
+        This allows flexible asset organization within the plugin.
+        """
+        base = self.get_plugin_source_dir()
+        return {
+            'js': base / 'js',
+            'css': base / 'static' / 'css',
+            'images': base / 'static' / 'images',
+            'templates': base / 'static' / 'templates',
+        }
+
     def get_required_assets(self) -> Dict[str, List[str]]:
-        """Define required JavaScript, CSS, and other assets."""
+        """
+        Define required JavaScript, CSS, and other assets.
+        All paths are relative to the plugin source directory.
+        """
         return {
             "js": [
-                "static/js/core/debug-system.js",
-                "static/js/core/section-manager.js",
-                "static/js/components/debug-panel.js",
-                "static/js/components/dom-renderer.js",
-                "../capabilities/testdrive-jsui/js/controls/control-base.js",
-                "../capabilities/testdrive-jsui/js/controls/contents-control.js",
-                "../capabilities/testdrive-jsui/js/controls/status-control.js",
-                "../capabilities/testdrive-jsui/js/controls/debug-control.js",
-                "../capabilities/testdrive-jsui/js/controls/edit-control.js",
-                "static/js/config-loader.js",
-                "static/js/main-updated.js"
+                "js/core/debug-system.js",
+                "js/core/section-manager.js",
+                "js/components/debug-panel.js",
+                "js/components/dom-renderer.js",
+                "js/controls/control-base.js",
+                "js/controls/contents-control.js",
+                "js/controls/status-control.js",
+                "js/controls/debug-control.js",
+                "js/controls/edit-control.js",
+                "js/config-loader.js",
+                "js/main-updated.js"
             ],
             "css": [
                 "static/css/editor.css",
@@ -57,9 +81,9 @@ class TestDriveJSUIEngine(RenderingEnginePlugin):
                 "static/css/themes/github.css"
             ],
             "images": [
-                "images/icons/edit.png",
-                "images/icons/save.png",
-                "images/icons/reset.png"
+                "static/images/icons/edit.png",
+                "static/images/icons/save.png",
+                "static/images/icons/reset.png"
             ],
             "external": [
                 "https://cdn.jsdelivr.net/npm/marked/marked.min.js"
@@ -68,15 +92,16 @@ class TestDriveJSUIEngine(RenderingEnginePlugin):
 
     def get_template_path(self) -> Optional[Path]:
         """Return path to the HTML template."""
-        # Look for template in plugin directory structure
-        plugin_dir = Path(__file__).parent.parent.parent / "testdrive-jsui"
-        template_path = plugin_dir / "templates" / "index.html"
+        # Template is in the plugin's static/templates directory
+        template_path = self.get_asset_paths()['templates'] / "index.html"
 
         if template_path.exists():
             return template_path
 
-        # Fallback to current template location
-        return Path(__file__).parent.parent / "templates" / "edit-mode-fixed.html"
+        raise FileNotFoundError(
+            f"Template not found at {template_path}. "
+            f"Ensure testdrive-jsui is properly installed in capabilities/"
+        )
 
     def render_document(self,
                        content: str,